One of the most important “river law” topics is the application of the Endangered Species Act to water management and use. The ESA is a crucial law for western rivers because it has been far more influential than anything else in making the environment a relevant factor in water management, especially in the operation of federal water projects. And federal river restoration efforts are overwhelmingly driven by ESA considerations.

The ESA is vital in this context, but the absence of other environmental laws with a similar impact on water management presents certain problems. For one thing, in places where there is no river-dependent species listed as threatened or endangered, environmental factors often carry little weight in water management. Without a listed species, water allocation and management often ignore the health of the river. And even where listed species do exist, focusing on the needs of a single species (as the ESA does) may do little or nothing for other wildlife, or for river recreation. In short, the ESA protects only one of the important values that rivers provide.

A more technical problem with the ESA is that certain key duties of federal agencies–to “consult” with expert agencies on the impacts of their proposed actions, and to avoid taking actions that would “jeopardize” protected species–do not apply if an agency action is not “discretionary.” This exception does not appear in the ESA itself, but in implementing regulations which the Supreme Court upheld in 2007. Thus, if a federal agency can show that it has no legal discretion in how it operates a water project, it can avoid some of its most important ESA duties. (I wrote about this issue in an article called “Dams, Duties and Discretion,” found at Vol. 33, p. 1 of the Columbia Journal of Environmental Law (2008).)

This issue reappeared last month on the Middle Rio Grande in my state of New Mexico. A decade ago, this basin saw years of bitter litigation that focused largely on whether the Bureau of Reclamation had discretion in operating its water projects. Ultimately all the court decisions were “vacated,” basically wiped off the books, including one that held that the Corps of Engineers had no discretion in operating its dams in the basin. So the Corps took a risk when it announced, in a Nov. 26 letter to the Fish & Wildlife Service, that it was withdrawing from ESA consultation over its Middle Rio Grande project operations while it determined whether its ongoing actions were “wholly non-discretionary and/or part of the environmental baseline.” (This letter pointed to a June 11, 2013 guidance document from Corps HQ, which stressed the need to protect the Corps’ budget from being “inappropriately diverted to pay for large-scale environmental restoration projects … in the guise of alleged ESA responsibilities that are not legitimately the Corps’ ….”)

The Corps could greatly help the cause of restoring the badly impaired Middle Rio Grande–and the endangered silvery minnow–by being flexible in its approach to river operations. But the legal incentives are perverse, because if the Corps can show that it has no discretion in project operations, it basically eliminates its ESA compliance burdens. If the Corps’ review of its actions on the Middle Rio Grande claims that the agency has no operating discretion, that would be good news for the Corps … but bad news for those who care about the river.